Manufacture of hollow bodies consisting of vulcanized rubber



'- mixture. The principal disadvantage of the 65 2. Improvement in themanufacture of 90 Patented June 24, 1930 UNITE STATES WILL-FRIED GENTH,OF-COLOGNE-STAMMHEIM, GERMANY, ASSIGNOR TO I. G. FARBEN- INDUSTBIEAK'IIENGESELLSCHAFT, 0F FRANKFORT-ON-THE-MAIN, GERMANY, A. CORPORATIONOF GERMANY MANUFACTURE OF HOLLOW BODIES CONSISTING 0F VULCANIZED RUBBER.

No Drawing. Application filed March 14, 1929, Serial No. 847,179, and.in Germany March 21, 1928.

The present invention concerns an imhollow articles consisting ofvulcanized rubprovement in the manufacture of hollow ber, comprisin theuse of metaldehyde as bodies (balls, squirts, douches, sponges or theaerating or in atlng agent in an amount of like) consisting ofvulcanized rubber. about O,51 gram calculated upon the forma- For themanufacture of such hollow bodies tion of balls of 10 cms. diameter. 60,

it has hitherto been customary to use liquid In testimony whereof I havehereunto set aerating or inflating agents or solutions or my hand.mixtures of ammonium chloride and sodium I I WVILFRIED GENTH. nitrite ina compressed form (see for instance 10 U. S. Patent 1,415,437.) Thelatter method represents a great advance over the liquid aerating orinflating agents, since the definite quantity present in the compressedagents enables a higher speed of working without en- 15 dangering thecertainty of the results.

An obvious disadvantage of all these methods, however, consists in thepoor stability of the compounds used and the action of the aerating orinflating agents on the rubber compressed nitrite is the poor capacityfor storage and the necessity of introducing small quantities of watersimultaneously with the compressed nitrite into the respective hollowbody. All these disadvantages are avoided by the use of metaldehyde. Itsufiices to employ metaldehyde, compressed into the Ar .desired shape,(for example, about 0,51

gram for balls of 10 cms. diameter), to pro- 30 duce an internalpressure, suflicient to press the rubber mixture to the walls of themold.

Also sponge like objects consisting of vulcanized rubbencan easily bemanufactured with the use of metaldehyde, by adding the latter in asuitable amount (for instance about 5%) to the rubber-vulcanizationmixture by rolling or the like and vulcanizing the mixture thus obtainedin a suitable mold according to known methods. 40 I claim:

1. Improvement in the manufacture of hollow articles and s onge likeobjects consisting of vulcanized ru ber, comprising the use ofmetaldehyde as aerating or inflating agent.

